This application is based on and claims priority under 35 U.S.C. xc2xa7119 with respect to a Japanese Patent Application 2002-104993, filed on Apr. 8, 2002, the entire content of which is incorporated herein by reference.
The present invention relates to an opening and closing control device of opening and closing member for a vehicle.
Recent vehicles including an opening and closing member such as a back door and a sunroof are provided with an opening and closing control device. The opening and closing member is operated by a motor which is driven so as to reach to a predetermined target speed. When the actual speed of the motor reaches to an entrapment judgment speed which is set lower than the target speed, the opening and closing control device detects entrapped obstacles and drives the motor in reverse direction.
In a conventional device, when the opening and closing member is operated, output duty fed to the motor is increased or decreased by feedback control on the basis of the difference between the target speed and the actual speed so as to close the actual speed to the target speed. One example of the conventional device is shown in FIG. 7. In this example, an artificial force is applied to the opening and closing member which is operated toward the opening condition and the opening speed of the opening and closing member is momentarily increased. FIG. 7(a) shows output duty which is supplied to the motor. The target speed of the motor and the actual speed which is obtained by feedback control in FIG. 7(b). Further, in FIG. 7(b), the predetermined entrapment judgment speed which is set lower than the target speed for judging entrapment of obstacles is shown. FIG. 7(c) shows a condition in which a flag is generated by the judgment of entrapped obstacles by the control device when the actual speed of the motor becomes lower than the entrapment judgment speed,
In the above prior control device, however, in case of that the opening speed of the opening and closing member is increased by, for example, the working of human power to the opening and closing member, erroneous judgment of entrapped obstacles is carried out as follows. As shown in FIG. 7(b), in this example, satisfactory control is carried out by feedback control first three seconds so as to coincide the actual speed of the motor with the target speed in this time, the output duty is increased or decreased properly by feedback control.
Then, when three seconds pass, the actual speed of the motor increases suddenly as shown in FIG. 7(b). When the actual speed increases suddenly, the feedback control operates remarkably and the control device decreases the output duty suddenly for approaching the excessive actual speed to the target speed. As shown in FIG. 7(a), as the output duty decreases, the actual speed begins to decrease suddenly about one second later too. The artificial external force which acts to the opening and closing member acts momentarily in usual. Accordingly, when the actual speed begins to decrease, the external force is usually removed. Thereby, the moving speed of the opening and closing member which is on the way of the opening operation decreases suddenly by the removal of the external force and the decrease of the output duty. As a result, the actual speed of the motor becomes lower than the target speed and further becomes lower than the entrapment judgment speed. The control device judges erroneously that this phenomenon corresponds to the entrapped obstacles and the flag of the entrapment judgment is generated as shown in FIG. 7(c).
In addition to this, for example, in case of that some rattle exist in a driving mechanism of the opening and closing member, the opening and closing member vibrates during opening and closing operation. In such case, excessive accelerate or decelerate by the feedback control occurs and the entrapped obstacles is erroneously judged.
It is an object of the present invention to provide an opening and closing control device of opening and closing member for a vehicle which can prevent the erroneous judgment of entrapped obstacles.
According to one aspect of the present invention, an opening and closing control device of opening and closing member for a vehicle includes a motor for actuating the opening and closing member, and a control means for driving the motor so as to become a predetermined target speed and for driving the motor in reverse direction as a detection of entrapped obstacles when the actual speed of the motor reaches to an entrapment judgment speed which is set lower than the target speed. The control means sets a threshold speed which is higher than the target speed and outputs an output duty to the motor for achieving the target speed by feedback control. The control means switches the output duty after the actual speed of the motor becomes higher than the threshold speed to an output by feedforward control based on the target speed.
According to another aspect of the present invention, an opening and closing control device of opening and closing member for a vehicle includes a motor for actuating the opening and closing member, and a control means for driving the motor so as to become a predetermined target speed and for driving the motor in reverse direction as a detection of entrapped obstacles when the actual speed of the motor reaches to an entrapment judgment speed which is set lower than the target speed. The control means sets a threshold speed which is higher than the target speed. The control means prohibits the judgment of the entrapment for a predetermined time from when the actual speed of the motor becomes lower than the threshold speed again after the actual speed becomes higher than the threshold speed.